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Discussion Starter #1
Ok, as some of you may know I just figured out tonight my solid flat tappet is shot. I just remembered I had a brand new Roller Hydraulic Trick Flow cam in stock. How close is it to the one I currently have and is it worth using or buy another solid? If I go with the roller I'll obviously need to incorporate the cost of new roller lifters and probably new push rods.

The Current solid is:

Basic Operating RPM Range: 4,000-7,500
Duration at 050 inch Lift: 252 int./260 exh.
Advertised Duration: 290 int./298 exh.
Valve Lift with Factory Rocker Arm Ratio: 0.536 int./0.554 exh. lift
Lobe Separation (degrees): 112

Hydraulic Roller:

Basic Operating RPM Range: 3,500-7,000
Duration at 050 inch Lift: 246 int./254 exh.
Advertised Duration: 308 int./316 exh. .
Valve Lift with Factory Rocker Arm Ratio: 0.558 int./0.558 exh. lift
Lobe Separation (degrees): 112
 

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as much compression u have ,,,

hmm ,,i've never done the hydraulic roller thang ,, as much as the lifters cost , you could just about get a solid roller cam and lifters and really nail down ur combo IMO. I think hydraulic roller lifters go for over 500 bux.

I'd get a new jegs catalog , get a contact high from the new ink , really think about things
 

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well look at it this way. With solid roller cams you need bigger springs, better pushrods, 7/16" rocker studs and roller rockers. Solid rollers take more spring pressure than hydraulic or solid flat tappet cams. Each cam and spring set up is different, as you know. My best advice would be to get the motor out and tear it down get all the metal shavings out clean it thoroughly. Check your spring pressures now see if you springs are okay. If they're good I'd do another solid flat tappet, maybe a more aggressive profile, tighten up the lobe centers. It's all about getting the most bang for the buck. If you need springs then think about changing over to a solid roller or whatever.
 

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Discussion Starter #6
well look at it this way. With solid roller cams you need bigger springs, better pushrods, 7/16" rocker studs and roller rockers. Solid rollers take more spring pressure than hydraulic or solid flat tappet cams. Each cam and spring set up is different, as you know. My best advice would be to get the motor out and tear it down get all the metal shavings out clean it thoroughly. Check your spring pressures now see if you springs are okay. If they're good I'd do another solid flat tappet, maybe a more aggressive profile, tighten up the lobe centers. It's all about getting the most bang for the buck. If you need springs then think about changing over to a solid roller or whatever.
I already have the roller rockers and girdles. Are you saying more Agressive lift or duration? What would going to a 110 or 108 LSA gain me?
 

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That hydraulic roller is pretty close to the solid you're pulling out. There are some VERY reasonable retro-fit lifters out there.
http://www.competitionproducts.com/prodinfo.asp?number=91164

For the $500-$600 everyone usually talks about, I can show you the retro-fit hydraulic roller lifters that are meant to set up with 160-170 pounds of seat pressure and use a VERY specific amount of pre-load (usually .002"-.005") to ensure they won't pump up. They're good to a bit over 7000 and shouldn't have a problem living on the street almost forever.:yes:
Then in the same price range are the MAX intensity hydraulic lifters that are meant to set up with around 200 pounds on the seat and will handle over 7500 but I have no idea what their street life would be.:no:

As for YOUR application, I'd look at a different solid flat tappet.:yes: Give Harold a call and get something out there will all of the intensity you can get that will FIT your application. Then use the CORRECT oil and break-in procedure and it should live forever.
Harold Brookshire's # 662-562-4933
 

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As long as you throw a degree wheel on her, and spec out the dimensions to be sure the duration/overlap won't change your piston/valve clearance, I say use it. Cams are damn expensive, and will probably go higher with one less competitor around (Crane r.i.p.)
 

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if it wuz me

I think i'd just stay solid flat and use better oil next round if the future wifey will get upset with a new roller package ,,lol

this motor has some compression ,, soo ,, and remembering a friend of mine used a cam similar to this in a street/strip Vega with a 327 with flat tops and double hump heads , 4000 stall with a turbo , and only a 411 gear with 18.50 x30 Hoosier tires ,, It would run 7.40's driven to the track and went in the 20's with a 8 inch converter ( i'd say this 327 didn't have even 9.5-1 ),, i'd look at this cam


http://www.lunatipower.com/Product.aspx?id=1793&gid=247
 

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a roller cam will allow the cam to open and close the valves faster, meaning the valves will be open longer for better flow through the cylinder heads, if your heads are just o.k. the roller cam won't give you th performance it should

a tighter lobe seperation, going from a 112 to say a 108 will narrow the power band and aid in the scavenging of the incoming air and fuel. more overlap (a tighter lsa) will benifit a normally aspirated motor provided all the other components are matched....

jon
 

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a roller cam will allow the cam to open and close the valves faster, meaning the valves will be open longer for better flow through the cylinder heads, if your heads are just o.k. the roller cam won't give you th performance it should

a tighter lobe seperation, going from a 112 to say a 108 will narrow the power band and aid in the scavenging of the incoming air and fuel. more overlap (a tighter lsa) will benifit a normally aspirated motor provided all the other components are matched....

jon
spot on reply
 

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1. a roller cam will allow the cam to open and close the valves faster, meaning the valves will be open longer for better flow through the cylinder heads, if your heads are just o.k. the roller cam won't give you the performance it should


jon
1. Not necessarily true.:no:
Some of the latest solid flat tappet cams I've had spec'd out had a hell-of-a-lot faster ramps than most of the so-called "Street rollers" out there. I'm now seeing 27*-28* of hydraulic intensity with solid flat tappets where 90% of your hydraulic rollers are still in the 42*-to-55* range (VERY slow ramps) and "Street Rollers" in the 35*-to-42* range with a whole host of their own known "Issues".
The whole idea of what you're mentioning is the actual "Area under the curve" which can be easily compared by looking at the Advertised duration #'s compared to the .050" duration #'s. The closer they are together, the more "Hydraulic Intensity" the lobe has, the faster it's getting the valve open and thus the more time it will stay open farther for a given amount of total (Advertised) duration.
For instance, 2 cams both with 290* advertised duration (measured at the same .002, typical hydraulic cams) one has 235* @ .050" lift and the other with 248* @ .050" lift. The second cam (with more duration @ .050") will have quite a bit more area under the curve for the same amount of given total duration and overlap. Cam #1 has 55* of hydraulic intensity and the second cam has 42* of intensity. .380"+ lobe lifts are becoming more and more common these days in the solid flat tappets. Just look at Harold's latest Voodoo Solid flat tappets. Most of which are all being designed with 29* of hydraulic intensity (actually more on the opening side since they're true asymmetrical designs) some of which have .386" lobe lift on the stock diameter .842" lifters!
When comparing hydraulic rollers to solid flat tappets the differences become even MORE profound. :yes:
Here's a couple of Harold's designs I posted in another thread.
Lunati part #60142
278 / 286
249 / 257
.540” / .560”
110 / 106
2800-7000
RPM range: 2800 - 7000

Lunati part #60143
286 / 294
257 / 265
.560” / .580”
110 / 106
3000-7200

Isky and Comp both have some 28* and 29* lobes available as well.
 

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just a general statement D-Man, there are exceptions to the rule, but for the most part a roller design is superior to a flat tappet design in that it "can" open the valve or valves longer and quicker and without the drag or potential problems that you may face with the reg. flat tappet design.

point taken though......:)

jon
 

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just a general statement D-Man, there are exceptions to the rule, but for the most part a roller design is superior to a flat tappet design in that it "can" open the valve or valves longer and quicker and without the drag or potential problems that you may face with the reg. flat tappet design.

point taken though......:)

jon
Absolutely. But 99% of what you see sold these days that's not the case. People are jumping all over 20 year old lobe designs like they are still the best thing since sliced bread and touting all of the old wives tales and folk lore like it's the facts.
The fact is, I have yet to see a hydraulic roller with more (or even close to as much) hydraulic intensity than what I can get with a sold flat tappet. Those roller designs aren't (and can't be) utilized with hydraulic style lifters.
And if the PROPER oil is used and the proper break-in procedure is followed we wouldn't see the problems with the flat tappet cams that are so common these days.:no:
I guess Veno wasted probably close to 1000 hours and a good chunk of cash to gather all of that info for everyone on this board since everyone ignores the sticky and continues to prove their brand loyalty is worth more than their engine.:rolleyes:
 

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you are correct D-Man, when you compare a solid flat tappet cam to a hydraulic roller cam, but not when you compare a solid roller to a solid flat tappet.......most of the time at least

the factory switched to hydraulic rollers to get gas mileage and to reduce friction in the engine/heat.....and in doing that it frees up a few ponies in the process
 

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you are correct D-Man, when you compare a solid flat tappet cam to a hydraulic roller cam, but not when you compare a solid roller to a solid flat tappet.......most of the time at least

the factory switched to hydraulic rollers to get gas mileage and to reduce friction in the engine/heat.....and in doing that it frees up a few ponies in the process
90% of the reason for the switch to hydraulic roller was because of the mandated emissions requirements which removed the zinc from the oils because the catalytic converters have to last 100k miles. Even at that, Honda and several other manufacturers still utilize solid cams in all of their "V-tec" engines and they don't seem to have any real service issues ie: Setting the valves frequently..:no:

This thread was started comparing a hydraulic roller to solid flat tappets. That's why I stuck with that. Yes, solid rollers can be quite a bit more "intense" but those profiles are NEVER recommended for any kind of street use because of the elevated spring pressures required to keep the valvetrain in check. Some people do but the lifters and springs don't last.:no: Comp recommends to have their solid roller lifters rebuilt every 3000 miles!:eek: Whereas unless the solid roller is the type of grind with over .390" lobe lift, there's really no reason for the added expense unless..
1. It's in a small displacement engine turning extremely high (7500+) RPM's
or
2. your valvetrain mass is too high to control with moderate spring pressures which can sometimes be common in big blocks.
or
3. You just want to be able to have the bragging rights of saying "I've got a solid roller in there."..
 

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D-Man, there are physical restrictions of flat tappets that only rollers can overcome. 90%? Jon is comparing apples to apples, you are not. A roller cam itself is billet so that it can take the punishment of huge valve spring pressures. A comparative flat tappet would melt under those conditions. The biggest hype about rollers is that they can ramp at crazy rates without the tappet leaving the cam like a flat lifter would. Automakers love the roller. They can get longevity and emissions efficiency all in one package. As Jon was explaining, the scavening effect is perfect for emissions, and easily accomplished with having the timing events occur rapidly, like a high ramping rate. That way the intake cycle can happen faster so the valves can slam shut, trapping unburnt fuel to be burned again, lowering the net tailpipe NOx. Sadly, that's all that matters to the engineers anymore. Think about it. If flat tappet technology was so great, they would use it for cost savings, if nothing else.
 

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D-Man, there are physical restrictions of flat tappets that only rollers can overcome. 90%? Jon is comparing apples to apples, you are not. A roller cam itself is billet so that it can take the punishment of huge valve spring pressures. A comparative flat tappet would melt under those conditions. The biggest hype about rollers is that they can ramp at crazy rates without the tappet leaving the cam like a flat lifter would. Automakers love the roller. They can get longevity and emissions efficiency all in one package. As Jon was explaining, the scavening effect is perfect for emissions, and easily accomplished with having the timing events occur rapidly, like a high ramping rate. That way the intake cycle can happen faster so the valves can slam shut, trapping unburnt fuel to be burned again, lowering the net tailpipe NOx. Sadly, that's all that matters to the engineers anymore. Think about it. If flat tappet technology was so great, they would use it for cost savings, if nothing else.
I'm not arguing the fact that the rollers CAN be designed with faster ramps.:no: Just the fact that they're NOT.
The original post was asking about (comparing) an aftermarket hydraulic roller and solid flat tappets. NOT OEM's, emissions, or solid rollers. I know there's plenty limitations to the flat lifters. I've dealt with plenty including billet cores, tool steel lifters, and over 200# of seat pressure on FLAT TAPPETS. Yes, at that level they suffer the same longevity problems of the radical solid rollers.:yes:

For what it's worth, don't think for a minute the factors hydraulic rollers have any kind of fast ramps at all.:no: Fast ramps require better valve springs and tend to be noisy. Neither of which fits what the OEM's want. The hydraulic intensity of the OEM's is typically over 50*.:yes:

As for the billet core comment.....90% to 95% of the roller cams sold by Comp are on SADI cores. They're CAST not BILLET. Some companies like Lunati grind ALL of their rollers on billet cores with either a cast distributor gear welded on or the billet gear is melonized so the use of a bronze or plastic (sacrificial) distributor gear isn't required.
And yes, it's still a common issue for the solid rollers to "Loft" the lifter off the lobe. There's even "Lift Rule" hydraulic roller profiles whose opening rates and fast enough (oddly enough have hydraulic intensity #'s close to the latest VooDoo series solid flat tappets) that they are DESIGNED to "LAUNCH" the lifter off the cam.:yes::rolleyes: They do so because, as PAUL mentioned in several other threads, the hydraulic roller lifters are typically very heavy.
 

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....90% to 95% of the roller cams sold by Comp are on SADI cores. They're CAST not BILLET.
D-Man, I didn't intend to split hairs with regard to brands. As I'm sure you've done your homework with Comp Cams, I'll guess that most rollers are made from billet for durability.

OEM surely didn't start using roller setups for horsepower numbers. They used them for the reasons I've described. Naturally, factory (HYD) rollers are going to be lame. They're simply rollerized replacements for flat tappets. HP gains were purely coincidental, most likely.

If I recall, the discussion changed excusively to ramp rates after your comments. For that discussion, I agree with you about limitations on OEM rollers. The added weight from the hydraulics and the extra gear for the roller may negate a lot of it's design benefits over older technologies. That's why I'm sure aftermarket HYD roller lifter appear segmented, in an effort to reduce that rotational mass you referenced.

Apples to apples: Hyd roller vs hyd flat tap? Roller wins
 
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